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Humans are creating significant global environmental change, including shifts in climate, increased nitrogen (N) deposition, and the facilitation of species invasions. A multi-factorial field experiment is being performed in an arid grassland within the Sevilleta National Wildlife Refuge (NWR) to simulate increased nighttime temperature, higher N deposition, and heightened El Nino frequency (which increases winter precipitation by an average of 50%). The purpose of the experiment is to better understand the potential effects of environmental drivers on grassland community composition, aboveground net primary production and soil respiration. The focus is on the response of two dominant grasses (Bouteloua gracilis and B eriopoda), in an ecotone near their range margins and thus these species may be particularly susceptible to global environmental change. It is hypothesized that warmer summer temperatures and increased evaporation will favor growth of black grama (Bouteloua eriopoda), a desert grass, but that increased winter precipitation and/or available nitrogen will favor the growth of blue grama (Bouteloua gracilis), a shortgrass prairie species. Treatment effects on limiting resources (soil moisture, nitrogen availability, species abundance, and net primary production (NPP) are all being measured to determine the interactive effects of key global change drivers on arid grassland plant community dynamics and ecosystem processes. This dataset shows values of soil moisture, soil temperature, and the CO2 flux of the amount of CO2 that has moved from soil to air. On 4 August 2009 lightning ignited a ~3300 ha wildfire that burned through the experiment and its surroundings. Because desert grassland fires are patchy, not all of the replicate plots burned in the wildfire. Therefore, seven days after the wildfire was extinguished, the Sevilleta NWR Fire Crew thoroughly burned the remaining plots allowing us to assess experimentally the effects of interactions among multiple global change presses and a pulse disturbance on post-fire grassland dynamics.
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Warming-El Nino-Nitrogen Deposition Experiment (WENNDEx): Net Primary Production Quadrat Data at the Sevilleta National Wildlife Refuge, New Mexico
{"Abstract":["Humans are creating significant global environmental change,\n including shifts in climate, increased nitrogen (N) deposition, and\n the facilitation of species invasions. A multi-factorial field\n experiment is being performed in an arid grassland within the\n Sevilleta National Wildlife Refuge (NWR) to simulate increased\n nighttime temperature, higher N deposition, and heightened El Niño\n frequency (which increases winter precipitation by an average of\n 50%). The purpose of the experiment is to better understand the\n potential effects of environmental change on grassland community\n composition and the growth of introduced creosote seeds and\n seedlings. The focus is on the response of three dominant species,\n all of which are near their range margins and thus may be\n particularly susceptible to environmental change. It is hypothesized\n that warmer summer temperatures and increased evaporation will favor\n growth of black grama (Bouteloua eriopoda), a desert grass, but that\n increased winter precipitation and/or available nitrogen will favor\n the growth of blue grama (Bouteloua gracilis), a shortgrass prairie\n species. Furthermore, it is thought that the growth and survival of\n introduced creosote (Larrea tridentata) seeds and seedlings will be\n promoted by heightened winter precipitation, N addition, and warmer\n nighttime temperatures. Treatment effects on limiting resources\n (soil moisture, nitrogen mineralization), species growth\n (photosynthetic rates, creosote shoot elongation), species\n abundance, and net primary production (NPP) are all being measured\n to determine the interactive effects of key global change drivers on\n arid grassland plant community dynamics. To measure above-ground NPP\n (i.e., the change in plant biomass, represented by stems, flowers,\n fruit and foliage, over time), the vegetation variables in this\n dataset, including species composition and the cover and height of\n individuals, are sampled twice yearly (spring and fall) at permanent\n 1m x 1m plots. The data from these plots is used to build\n regressions correlating biomass and volume via weights of select\n harvested species obtained in SEV157, "Net Primary Productivity\n (NPP) Weight Data." This biomass data is included in SEV205,\n "Warming-El Nino-Nitrogen Deposition Experiment (WENNDEx):\n Seasonal Biomass and Seasonal and Annual NPP.""]}
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- PAR ID:
- 10424123
- Publisher / Repository:
- Environmental Data Initiative
- Date Published:
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Humans are creating significant global environmental change, including shifts in climate, increased nitrogen (N) deposition, and the facilitation of species invasions. A multi-factorial field experiment is being performed in an arid grassland within the Sevilleta National Wildlife Refuge (NWR) to simulate increased nighttime temperature, higher N deposition, and heightened El Niño frequency (which increases winter precipitation by an average of 50%). The purpose of the experiment is to better understand the potential effects of environmental drivers on grassland community composition, aboveground net primary production and soil respiration. The focus is on the response of two dominant grasses (Bouteloua gracilis and B eriopoda), in an ecotone near their range margins and thus these species may be particularly susceptible to global environmental change. It is hypothesized that warmer summer temperatures and increased evaporation will favor growth of black grama (Bouteloua eriopoda), a desert grass, but that increased winter precipitation and/or available nitrogen will favor the growth of blue grama (Bouteloua gracilis), a shortgrass prairie species. Treatment effects on limiting resources (soil moisture, nitrogen availability, species abundance, and net primary production (NPP) are all being measured to determine the interactive effects of key global change drivers on arid grassland plant community dynamics and ecosystem processes. On 4 August 2009 lightning ignited a ~3300 ha wildfire that burned through the experiment and its surroundings. Because desert grassland fires are patchy, not all of the replicate plots burned in the wildfire. Therefore, seven days after the wildfire was extinguished, the Sevilleta NWR Fire Crew thoroughly burned the remaining plots allowing us to assess experimentally the effects of interactions among multiple global change presses and a pulse disturbance on post-fire grassland dynamics. This data set provides soil N availability in each plot of the warming experiment for the monsoon season (also see SEV176).more » « less
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{"Abstract":["This dataset contains pinon-juniper woodland quadrat data and is\n part of a long-term study at the Sevilleta LTER measuring net\n primary production (NPP) across four distinct ecosystems:\n creosote-dominant shrubland (Site C, est. winter 1999), black\n grama-dominant grassland (Site G, est. winter 1999), blue\n grama-dominant grassland (Site B, est. winter 2002), and\n pinon-juniper woodland (Site P, est. winter 2003). Net primary\n production is a fundamental ecological variable that quantifies\n rates of carbon consumption and fixation. Estimates of NPP are\n important in understanding energy flow at a community level as well\n as spatial and temporal responses to a range of ecological\n processes. Above-ground net primary production is the change in\n plant biomass, represented by stems, flowers, fruit and and foliage,\n over time and incorporates growth as well as loss to death and\n decomposition. To measure this change the vegetation variables in\n this dataset, including species composition and the cover and height\n of individuals, are sampled twice yearly (spring and fall) at\n permanent 1m x 1m plots within each site. A third sampling at Site C\n is performed in the winter. The data from these plots is used to\n build regressions correlating biomass and volume via weights of\n select harvested species obtained in SEV157, "Net Primary\n Productivity (NPP) Weight Data." This biomass data is included\n in SEV182, "Seasonal Biomass and Seasonal and Annual NPP for\n Core Research Sites.""]}more » « less
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{"Abstract":["This dataset contains pinon-juniper woodland biomass data and is\n part of a long-term study at the Sevilleta LTER measuring net\n primary production (NPP) across four distinct ecosystems:\n creosote-dominant shrubland (Site C, est. winter 1999), black\n grama-dominant grassland (Site G, est. winter 1999), blue\n grama-dominant grassland (Site B, est. winter 2002), and\n pinon-juniper woodland (Site P, est. winter 2003). Net primary\n production is a fundamental ecological variable that quantifies\n rates of carbon consumption and fixation. Estimates of NPP are\n important in understanding energy flow at a community level as well\n as spatial and temporal responses to a range of ecological\n processes. Above-ground net primary production is the change in\n plant biomass, represented by stems, flowers, fruit and and foliage,\n over time and incoporates growth as well as loss to death and\n decomposition. To measure this change the vegetation variables in\n this dataset, including species composition and the cover and height\n of individuals, are sampled twice yearly (spring and fall) at\n permanent 1m x 1m plots within each site. A third sampling at Site C\n is performed in the winter. Volumetric measurements are made using\n vegetation data from permanent plots (SEV278, "Pinon-Juniper\n (Core Site) Quadrat Data for the Net Primary Production Study")\n and regressions correlating species biomass and volume constructed\n using seasonal harvest weights from SEV157, "Net Primary\n Productivity (NPP) Weight Data.""]}more » « less
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